Photoprocessing of printed circuit board panels for the etching and deposition of patterns on the printed circuit board panel surfaces requires accurate positioning of the patterns on the phototools relative to patterns (e.g., drilled holes, copper features) already defined on the printed circuit board panel.
Techniques presently used in aligning the phototools to the printed circuit board panels range from "eye-bailing it" to the use of complex vision feedback systems to position the phototools. Examples of more accurate extant processes are very labor intensive and often require expensive panel-phototool positioning operations or complex aligning equipment. These existing processes are often very dependent on operator expertise for their accuracy.